Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description states that missing fields, conflicts, and hypothetical/disputed/historical wording are disclosed, and that 'news mentions never update source rates' — a key state-behavior guarantee. This goes well beyond the readOnly/idempotent annotations and tells the agent what side effects (or lack thereof) to expect.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Five tight sentences are front-loaded with purpose, then scope, behavior, and prohibitions. Nothing is redundant with the title or schema, and every clause adds decision-relevant detail.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers inputs, scoping, output hints (occurrenceReference with counts/rates/units), and edge-case handling, which is substantial for a tool with no output schema. The only minor gap is that 'occurrenceReference' is mentioned without explicitly labeling it as part of the response, which could momentarily confuse an agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With zero schema description coverage, the description compensates by explaining that title is the headline and referenceContext adds explicit country, magnitude, industry, or aviation scope. It doesn't spell out the enum codes or numeric limits, but it gives the semantic purpose of each parameter rather than just echoing the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The opening sentence names a specific operation ('Classify one supplied headline and inspect coverage recurrence') on a specific resource, and the title anchors it to Probable's observed base rates. This clearly separates it from the sibling watch/edition/event tools, none of which perform headline scoring.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It sets clear scope: one supplied headline, optional referenceContext for scope, and explicit prohibitions ('Do not verify a headline, compare incompatible units, predict an outcome, or score a URL'). It does not name alternative tools, but given the sibling set this is not necessary; the when-not guidance is concrete.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.